/****************************************************************************
 *
 * Copyright 2016 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 *
 ****************************************************************************/
/****************************************************************************
 * libc/stdio/lib_fclose.c
 *
 *   Copyright (C) 2007-2009, 2011, 3013 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <tinyara/config.h>

#include <unistd.h>
#include <stdlib.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>

#include "lib_internal.h"

/****************************************************************************
 * Global Functions
 ****************************************************************************/

/****************************************************************************
 * Name: fclose
 *
 * Description
 *   The fclose() function will flush the stream pointed to by stream
 *   (writing any buffered output data using lib_fflush()) and close the
 *   underlying file descriptor.
 *
 * Returned Value:
 *   Upon successful completion 0 is returned. Otherwise, EOF is returned
 *   and the global variable errno is set to indicate the error. In either
 *   case any further access (including another call to fclose()) to the
 *   stream results in undefined behaviour.
 *
 ****************************************************************************/

int fclose(FAR FILE *stream)
{
	int err = EINVAL;
	int ret = ERROR;
	int status;

	/* Verify that a stream was provided. */

	if (stream) {
		/* Check that the underlying file descriptor corresponds to an an open
		 * file.
		 */

		ret = OK;
		if (stream->fs_fd >= 0) {
			/* If the stream was opened for writing, then flush the stream */

			if ((stream->fs_oflags & O_WROK) != 0) {
				ret = lib_fflush(stream, true);
				err = errno;
			}

			/* Close the underlying file descriptor and save the return status */

			status = close(stream->fs_fd);

			/* If close() returns an error but flush() did not then make sure
			 * that we return the close() error condition.
			 */

			if (ret == OK) {
				ret = status;
				err = errno;
			}
		}
#if CONFIG_STDIO_BUFFER_SIZE > 0
		/* Destroy the semaphore */

		sem_destroy(&stream->fs_sem);

		/* Release the buffer */

		if (stream->fs_bufstart) {
			lib_free(stream->fs_bufstart);
		}

		/* Clear the whole structure */

		memset(stream, 0, sizeof(FILE));
#else
#if CONFIG_NUNGET_CHARS > 0
		/* Reset the number of ungetc characters */

		stream->fs_nungotten = 0;
#endif
		/* Reset the flags */

		stream->fs_oflags = 0;
#endif
		/* Setting the file descriptor to -1 makes the stream available for reuse */

		stream->fs_fd = -1;
	}

	/* On an error, reset the errno to the first error encountered and return
	 * EOF.
	 */

	if (ret != OK) {
		set_errno(err);
		return EOF;
	}

	/* Return success */

	return OK;
}
